1. Field of the Invention
The invention relates to a method for increasing production from a well through the use of an apparatus that perforates and slots through casing, cement bond and into a rock formation so as to increase conductivity between oil, gas, and/or water in the rock formation.
2. Background Art
Making deep slots in rock formations increases conductivity by opening permeable beds and fractures that are intersected by the well or are located near the well within the distance of the slot depth. Deep slots improve the conductivity of the well where the depth of the slots extend beyond a rock formation zone that has been damaged by stress, or extend beyond a region of pore clogging around a well that has caused a reduction is the permeability of the rock.
A method and apparatus for cutting round perforations and elongated slots in well flow conductors was offered in U.S. Pat. No. 4,134,453, which disclosure is incorporated herein by reference. The disclosed apparatus has jet nozzles in a jet nozzle head for discharging a fluid to cut the perforations and slots. The length of the cuts that the disclosed jet nozzle makes into the rock formation is limited because the jet nozzle is stationary with respect to the jet nozzle head.
A method and apparatus for cutting panel shaped openings is disclosed in U.S. Pat. No. 4,479,541, which disclosure is incorporated herein by reference. The disclosed apparatus, a perforator, has two expandable arms, each arm having an end with a jet thereat, the jet emitting a jet stream therefrom. The cutting function is disclosed as being accomplished by longitudinally oscillating, or reciprocating, the perforator. By a sequence of excursions up and down within a particular well segment, a deep slot is supposed to be formed. The offered method cannot, however, be performed because only an upward motion along a well is possible due to the design of the expandable arms. Further, a motion in a downward direction will be stopped by the two expandable arms which set against the well wall. As a result of the very sharp angle formed between the well wall and jet streams emitted at the jets at the ends of the expandable arms, only small scratches will be cut in the well walls.